Devices for visualizing patient and object image data typically include an image display means, at least one video camera and a computer-assisted navigation system, which can detect the spatial positions of the display device and/or the video camera as well as the spatial position of a part of the patient's body via tracking means attached to it. The devices serve to visually assist a physician when diagnosing and/or treating a patient. The intention is to provide the option of combining images from the interior of the patient with conventional video images, to order to facilitate treatment and diagnosis.
A generic, video-based surgical target system is known from U.S. Pat. No. 5,765,561, in which the use of a tracked camera is proposed, where the images from which are superimposed together with associated images from transillumination and/or tomographic imaging methods on the statically arranged screen of a navigation system. U.S. Pat. No. 5,715,836 also describes superimposing images from different sources in an operation or treatment environment. The images can come from computer tomography, nuclear spin tomography, ultrasound or x-ray image apparatus. Here too the images are outputted on a stationary screen.
Positional verification for positional markings in a video camera image, wherein video cameras and infrared cameras are combined and their images superimposed, is known from DE 19 848 765 A1. Here too the images are outputted on a stationary screen.
A disadvantage of the devices described above is that a physician who wishes to view the images always has to look away from the patient to the screen of the navigation system. He can thus no longer pay exact attention to what position the camera is then in, i.e., from what exterior position exactly he is receiving the superimposed images. The system is, therefore, awkward and does not enable a direct view into the part of the patient's body. Furthermore, all the inputs that the physician proposes to make into the system have to be made at the input station of the navigation system or treatment planning system. Thus, the physician again has to turn away from the patient and cannot directly verify the effect of the inputs.